The power supply of a Xiaomi laptop is not just a black box with wires, but a complex electronic device that can eventually fail. The causes of breakdowns are diverse: from banal overheating to power surges on the network. If your adapter stopped charging the laptop, makes extraneous sounds or warms up stronger than usual, disassembly can help diagnose the problem β whether it is bloated capacitors, burned resistors or damaged tracks on the board.
But disassembling the power supply is not an easy task. Unlike smartphone cases, where it is often enough to disconnect the latches, Xiaomi adapters (especially models for Mi Notebook Pro, RedmiBook or Mi Gaming Laptop) are assembled using glue, ultrasonic welding and even hidden screws. In this article, we will tell you how to disassemble the power supply without damage, what tools you need, and what to look for to avoid exacerbating the breakdown.
We warn you right away that working with power supplies is associated with the risk of electric shock, even if the device is disconnected from the network. If you are not sure about your skills, you should consult a specialist. But if you decide to act on your own, follow our recommendations and do not miss the sections with security measures.
Preparation for disassembly: tools and security measures
Before you start disassembling, make sure you have everything you need. Without the right tools, you risk damaging the body or internal components, and without safety, getting electrocuted or burning the board.
Here is the minimum set of tools you will need:
- π§ Set of screwdrivers (cross and flat, including T5, T6, T8 β They are most commonly used in Xiaomi blocks).
- π¨ Plastic mediators or blades for disconnecting the glued parts of the body.
- π₯ Dryer or heat-air station (if the body is glued with heat glue).
- 𧲠Magnetic mat or screw tray β they are small and easily lost.
- πΈ Smartphone for photographing each stage of disassembly (useful when reassembling).
- π‘οΈ Dielectric gloves and mat (if you plan to check the charge under voltage).
- π loope USB-microscope.
Also prepare the workplace: it should be well lit, without carpeting (so as not to lose screws) and with access to the outlet (if you need to test the unit after repair). USB-C (For example, from Xiaomi Mi Notebook Air, note that there may be additional protective circuits inside that are difficult to diagnose without a multimeter.
β οΈ Warning: Never disassemble a power supply connected to the network! Even when off, capacitors can store a charge of up to 300 V. Before starting work, disconnect the adapter from the socket and laptop, and then shorten the outputs of the capacitors with a screwdriver with an insulated handle (if you can do this).
Definition of the power supply model and its design
Xiaomi power supplies for laptops are divided into several types depending on the model of the device and the year of release.
- π¦ Classic adapters (for Mi Notebook Pro) 15.6", RedmiBook 14/16) β rectangular shape, with a collapsible body on screws.
- π Compact blocks with USB-C (Mi Notebook Air, Mi Gaming Laptop β often glued together, with minimalist design.
- β‘ Quick charging units (e.g. Xiaomi) 100W GaN) β use gallium nitride transistor technologies, it is extremely difficult to disassemble them without damage.
To understand how your block is being disassembled, first look for its model, which is shown on the back sticker in ADP-xxXY format (e.g., the model, ADP-65JD B for 65W adapter. Also note:
- π§ Type of mounting of the body: screws (hidden under legs or stickers) or glue.
- π Type of connector: round plug or USB-C.
- β οΈ Presence of warranty seals β if they are damaged, the warranty will burn.
If your unit is a GaN (gallium nitride) series, note that their body is often ultrasonically welded, and it is almost impossible to disassemble it without special equipment.
How to find out the power supply unit by model?
| Laptop model | Model of the power supply unit | Type of body | Difficulty disassembling |
|---|---|---|---|
| Mi Notebook Pro 15.6" | ADP-65JD B | Screws + latches | Medium |
| RedmiBook 14/16 | ADP-65JB | Glue + screws | Tall. |
| Mi Notebook Air 13.3" | ADP-45JD | Ultrasonic welding | Very high. |
| Mi Gaming Laptop | ADP-180JD | Screws. + heat-glue | Tall. |
Step-by-step: how to disassemble the power supply Xiaomi
Now, to the process itself, we'll look at a universal algorithm that works for most Xiaomi units on screws. If your adapter is glued, skip the unscrew steps and use a hairdryer (more on this below).
Step 1: Removing the sticker and finding hidden screws
On the back of the block, there's usually a specification sticker, and you should carefully put it in with a knife or a plastic card, which is often covered with screws, ADP-65JB) The screws are hidden under the rubber legs.
Step 2: Spinning the screws
Use a screwdriver of the right size (usually) T6 or T8). The screws can be of different lengths β remember which one is from, or fold them in separate containers. Don't put too much force on them: if the screw doesn't go, it may be glued (try heating the case with a hairdryer).
Step 3: Separation of the hull
After removing the screws, insert the plastic mediator into the gap between the halves of the body and carefully separate them as you move around the perimeter. If the body does not respond, then it is glued together.
- π₯ Heat the hair dryer seam around the perimeter (temperature) ~80-100Β°C).
- πͺ Repeat the attempt to disconnect with the mediator.
- β οΈ Donβt use metal tools β they will leave scratches.
Step 4: Extracting the fee
When you open the case, you'll see a board that's locked in screws or silicone pads, unscrew them and carefully pull out the board without pulling the wires.
- π Solder joints β if they are cracked, this can be the cause of malfunction.
- π₯ Bloated capacitors - a sign of overheating.
- π οΈ Darkened resistors or chips - a signal about breakdown.
I took a picture of the block from all sides.|
Prepared tools and workplace|
Disconnected the block from the network and laptop|
Checked for hidden screws under the stickers|
Wearing dielectric gloves (if you test under stress)-->
β οΈ Warning: If you find black spots on the board or the smell of burning, do not turn the block on the network! This is a sign of short circuit, and trying to apply the voltage can lead to fire. In such cases, repairs are usually unprofitable - it is cheaper to buy a new adapter.
Diagnostics of malfunctions: what to look for inside the block
After the dismantling, itβs time to check the charge for damage, and here are the most common causes of Xiaomi power supply failures:
1. Bloated or leaking capacitors
Capacitors are cylindrical-shaped "banks" that, if the top is convex or brown-painted, need to be replaced. 470 ΞΌf/25B 1000 ΞΌf/16B (e.g. in models) ADP-65JD).
2. Burnt resistors or diodes
Blackened or cracked resistors (small cylinders with colored stripes) are a sure sign of overload. Also check diodes (black βpillsβ with a stripe): if they are pierced, their resistance will be zero (checked by a multimeter in diode mode).
3. Damaged tracks or rations
Check the board for micro-cracks in the tracks or cold soldering (grey plaque around the legs of the elements). Often this is due to mechanical shocks or overheating. Pay special attention to the area around the elements. USB-C Circuit β there are often contacts.
4. Faulty transformer or throttle
A transformer is a large cube in the center of the board, wrapped in a wire. If it cracks or darkens, the block is to be replaced. The throttles are checked with a multimeter on the cliff.
5. Problems with the power connector
If the block doesn't show signs of life, but the board is visually intact, the problem could be the connector.
- π Integrity of the cable (often rubbed at the base).
- π§ Fixing the connector to the board - sometimes the contact platforms are torn off.
- π The voltage at the outlet (must correspond to the indicated on the sticker, for example, 19.5V For RedmiBook 14).
π‘
If you are not sure about your soldering skills, but want to try to repair the unit yourself, start with the simplest operations: replacing capacitors or soldering off wires. Complex elements (chips, transformers) are better left to professionals.
Power supply repair: what can be done on your own
If you find a fault that can be fixed without special equipment, here are some repair tips:
1. Replacement of capacitors
This will require a soldering iron, solder and new capacitors (buy with the same parameters: capacity, voltage, size).
- π₯ Heat the capacitor legs with a soldering iron and remove it.
- π§Ή Clean the holes from the old solder.
- π§ Insert a new capacitor, observing polarity (minus marked on the board).
- π₯ Suck your legs and cut off the extra conclusions.
2. Restoration of tracks
If the track is damaged, it can be repaired by:
- π¨ Wire bridge (thin wire soldered over a crack).
- ποΈ Current-conducting glue (suitable for minor damages).
Before soldering, clean the place of damage with alcohol or eraser.
Replacement of the power connector
If I connect USB-C Or a round plug is shattered, you can cut it over, buy a similar connector on AliExpress or at a radio store:
- π The contacts did not close together.
- π₯ Do not overheat the charge (use heat sink).
4. Cleaning of boards against dust and oxidation
Dust and oxides can cause current leaks. Use:
- 𧴠Isopropyl alcohol (at least 90%).
- 𧽠Soft brush or toothpick.
Donβt use acetone or solvents β they will damage the board!
π‘
If the unit is not working after repair, check it with a multimeter in voltage measurement mode. Connect the unit to the mains and measure the voltage at the output contacts. If it is absent or greatly underestimated, the problem is more serious than it seemed.
When repairs are inappropriate: signs of hopeless breakdowns
Not all power supply malfunctions can be fixed at home, but here are the cases when repairs don't make sense:
1.The controller chip burned down
If the main chip has burned (usually marked PIxxxx, RTxxx or MPxxxx), its replacement requires specialized equipment (soldling station, thermal air) and skills. BGA-The cost of repairs often exceeds the price of a new unit.
2.Transformer damaged
Transformers in Xiaomi blocks rarely fail, but if this happens (cracks, winding breaks), it is almost impossible to replace them - they are made to order for a particular model.
3. Short circuit in the primary circuit
If you connect to the network, the unit sparks, smokes or knocks the machine in the shield, it is a sign of high-voltage KZ. Repair is dangerous and requires deep knowledge in electronics.
4. Physical destruction of the fee
Cracks in the board, chipped fragments or traces of melting (especially near the power transistor) are a sure sign that it is time to throw the block away.
In such cases, it is more rational to buy a new adapter. Original power supplies for Xiaomi laptops cost from 1,500 to 4000 rubles depending on the model. Non-original analogues are cheaper, but their quality often leaves much to be desired.
β οΈ Note: If you decide to buy a new unit, make sure that its characteristics (voltage, current, power) are completely the same as the original. 65W/19.5V It is not suitable for a laptop that needs to be 100W/20V β This can lead to slow charging or overheating.
Assembly of the power supply and testing
After repair or diagnosis, the unit must be properly assembled.
1. Checking fees
Before assembly, check the fee again:
- π Make sure all the items are in place.
- π§ Check the quality of the soldering (no cold contacts).
- π§Ή Remove the remnants of flux with alcohol.
2. Laying of the board in the case
Carefully place the fee back, making sure:
- π The wires didn't twist or get under the screws.
- π οΈ Contact areas are not closed to the body.
Closing of the hull
You can combine the halves of the body and screw them together. If the body has been glued, use heat-glue or double-sided tape to fix it. Don't use superglue, it can damage the plastic!
4. Testing
Connect the block to the laptop and check:
- π Does the charging start.
- π‘οΈ Is the unit heated (normally it should be warm, but not hot).
- π Does the laptop show the correct voltage (can be checked in the BIOS program AIDA64).
If the block is unstable (it charges, then it does not), disassemble it again and check:
- π Quality of connector contacts.
- π§ Reliability of rations.
- π₯ Temperature of key elements (capacitors, transistors) β they should not overheat.
π‘
If the unit becomes noisy after assembly (squeaking or buzzing), this may be a sign of unstable operation of the transformer or throttle, in which case it is better not to use the adapter - it can fail and damage the laptop.